Command Enabling : Command « Windows Presentation Foundation « VB.Net Tutorial






<Window x:Class="WpfApplication1.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="CommandEnabling" Height="300" Width="300"
    >
  <Grid>
    <Menu VerticalAlignment="Top">
      <MenuItem Header="_Edit">
        <MenuItem Command="Redo" />
      </MenuItem>
    </Menu>
  </Grid>
</Window>



//File:Window.xaml.vb
Imports System
Imports System.Collections.Generic
Imports System.Text
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Data
Imports System.Windows.Documents
Imports System.Windows.Input
Imports System.Windows.Media
Imports System.Windows.Media.Imaging
Imports System.Windows.Shapes


Namespace WpfApplication1
  Public Partial Class Window1
    Inherits System.Windows.Window
    Public Sub New()
      InitializeComponent()

      Dim redoCommandBinding As New CommandBinding(ApplicationCommands.Redo)
      AddHandler redoCommandBinding.CanExecute, AddressOf RedoCommandCanExecute
      CommandBindings.Add(redoCommandBinding)
    End Sub

    Private Sub RedoCommandCanExecute(sender As Object, e As CanExecuteRoutedEventArgs)
      e.CanExecute = DateTime.Now.Second Mod 2 > 1
    End Sub
  End Class
End Namespace
WPF Command Enabling








16.89.Command
16.89.1.Invoking Copy command with a ButtonInvoking Copy command with a Button
16.89.2.Button CommandTarget BindingButton CommandTarget Binding
16.89.3.Creating CommandBinding and attaching an Executed and CanExecute handlerCreating CommandBinding and attaching an Executed and CanExecute handler
16.89.4.Command Handler Command Binding in XamlCommand Handler Command Binding in Xaml
16.89.5.Property changed callbackProperty changed callback
16.89.6.Using CommandBinding and ExecutedRoutedEventHandler to bind Application event to an event handler methodUsing CommandBinding and ExecutedRoutedEventHandler to bind Application event to an event handler method
16.89.7.Create CommandBindings in Xaml and bind to ButtonCreate CommandBindings in Xaml and bind to Button
16.89.8.Bind TextBox save command to CommandBindingBind TextBox save command to CommandBinding
16.89.9.Press F1 to get helpPress F1 to get help
16.89.10.Help commandHelp command
16.89.11.Command EnablingCommand Enabling